Some 28,000 savers have opened a cash Lifetime Isa since the deal was first launched by a building society in June.
Skipton Building Society said there has been a "high level of interest" in the account, with 28,000 people having opened its deal since it became available in early June.
Lifetime Isas, or Lisas, can be opened by people aged between 18 and 39 to save for their first home, or their retirement, in the same pot with a Government bonus added. Lisas were unveiled during the Budget in March 2016.
Skipton said 51% of its cash Lifetime Isa holders are under 30 and 6% are aged 39. Its figures are for the period June 6 to July 18.
Kris Brewster, head of products at Skipton Building Society said: "Since launching the UK's first cash Lifetime Isa in June, there continues to be a high level of interest in the product, particularly from those who want to save for their first home."
Some providers, including Hargreaves Lansdown and Nutmeg, launched investment versions of the Lifetime Isa when the scheme got under way in April 2017.
Many of Britain's biggest banks said when the scheme launched that they had no immediate plans to offer a Lisa, or that they were reviewing their position.
Skipton's deal pays 0.5% annual interest and it can be opened online with £1. First-time buyers who decide to take out a mortgage with Skipton, either directly or via intermediaries, will also receive £250 cashback.
Lisa schemes allow people to put away up to £4,000 each year and receive a Government bonus of up to £1,000 a year on their contributions until they turn 50.
Over their lifetime, people saving into a Lifetime Isa could potentially get a maximum bonus of £32,000.
Savings can be used to buy a first home or used for other purposes after the saver reaches 60.
Critics of the scheme generally have warned that savers could face charges for withdrawing their money before 60 for reasons other than buying their first home and also that some people may choose to save into a Lifetime Isa instead of a workplace pension, which has the benefits of "free money" from employers' contributions as well as tax relief.